1. Field of the Invention
The present invention relates to push button switches, and more particularly to push button switches which are used in combination with so-called "joy-stick" controllers.
2. Prior Art
Mechanical actuating lever controllers, commonly referred to as joy-stick actuators, are widely used in industry as a part of automatic control systems. In the copending application Ser. No. 110,969 filed Jan. 10, 1980 there are disclosed joy-stick actuators which have a shaft fitted to a pivot member, a socket holding the pivot member, a follower member having a central opening to receive a lobe protruding from the lower portion of the pivot member, and an electrical output device. Movement of the actuator shaft results in a movement of the lobe and subsequent movement of the follower member which positions a moving element of the output device.
Controllers of this type can be used, for example, to position a work piece below a cutting machine: movement of the actuator shaft in a given direction activating the output transducer to operate a work piece moving device to move a work piece in a similar direction. When more than one transducer is mounted within the controller adjacent the follower member, it is possible to generate signals from the transducers which can activate machinery to move work piece to any position on a plane.
It is desirable to incorporate a push button operated switch in the actuator shaft of this type of controller so that an additional function may be activated. For example, once a work piece is in the desired position, a push button located in the handle may be depressed to close a switch thereby activating a cutting torch to begin a cutting operation. In addition, it is also desirable to place a push button in the actuator shaft of a controller such that no lead wires travel from a movable member thus preventing fraying or shorting of the wires. Such a switch must be easily operable regardless of the degree of tilt of the actuator shaft relative to the body of the controller.